Torrefaction of biomass is one possible solution to the need for high grade fuels to replace dwindling fossil fuel reserves.
Torrefaction removes volatile products and prevents the biomass rotting. The volatile Hydro Carbons released during the process can be used to heat the Torrefaction tower once other fuels have been used to initiate the reaction.
Compressing the torrefied product into pellets or briquettes increases the fuel density and makes its distribution more efficient.
Hydro Thermal conversion of agricultural waste into biofuels is a recent development, allowing Orange peel and Onion skins to be economically converted into high grade pellets.
It requires the organic material to be soaked in an acid bath and heated under pressure for several hours.
Gasification by pyrolysis produces a low grade gas containing amongst other things hydrogen and carbon monoxide. It can be used for cogeneration in internal combustion engines to produce electricity and as a bi-product heat.
Anaerobic digestion produces methane from organic waste in an oxygen free environment.
This gas is also used in combined heat and power (CHP) systems.